Three dimensional stereoscopic image display technology has become the current trend in the image display technology field. The imaging theorem for the three dimensional stereoscopic image involves that seeing a target object by a left eye and a right eye to get the different images, thereby forming depth perceptions with farness and nearness. Multiple devices can be utilized to render the left eye and the right eye to see images with different views. Three dimensional image display devices can be classified as a glasses type and a bare-eye type. In the glasses type 3D image display devices, the most common ones involve the usage of shutter glasses, polarization glasses, anaglyph glasses, and pulfrich glasses. In the bare-eye type 3D image display devices, the most common ones are an eHolographic type, a volumetric type and a multiplexed 2-D type. The multiplexed 2-D type can be further classified as a spatial-multiplexed type, a time-multiplexed type and a tracking-based type.
Recently, the relatively mature and common stereoscopic display technique in the market is the glasses type stereoscopic display technique, and the shutter glasses is the relatively common glasses type stereoscopic display device in the market, where Nvidia is the most representative one. No matter what kinds of devices are used, the methods for generating different information for the left eye and the right eye are similar. Generally, different images are provided to the left eye and the right eye respectively to generate stereoscopic perceptions. The basic principle for generating stereoscopic image is based on that a left eye and a right eye separately see the object from different angles, i.e. the images observed from the left eye and the right eye are not completely the same. In the 3D glasses display system, 2D images of two different angles of view (L, R) are received by the left eyeglass and the right eyeglass at different times. When the left eye information is shown in the display, the right eyeglass is sheltered and the left eyeglass is transparent, and vice versa. Therefore, the left eye can see the left eye image only and the right eye can see the right eye image only.
Currently, the 3D glasses are classified as active type 3D glasses and passive type 3D glasses. The active type 3D glasses are the relatively common 3D glasses in the market, but it suffers some problems. For example, the active type 3D glasses need batteries and therefore it induces the charging problem and it does not satisfy the environmental protection concept. Furthermore, the effective distance between the active type 3D glasses and the emitter is limited and the signal emitted from the emitter may be shielded by any objects between the active type 3D glasses and the emitter. Moreover, the active type 3D glasses are expensive. On the contrary, the structure of the passive type 3D glasses is simple and can solve the problems of the active type 3D glasses. Currently, the passive type 3D glasses are utilized in the micro-retarder system to apply in 3D visualization. For example, in the micro-retarder system, the first line is employed for the right eye image and the second line is used to provide the left eye image. The left eye image information and the right eye image information are provided in order from the top to the bottom of the display, and the vertical resolution of the display will be downgraded because the pixels of the display are separated to show the left eye image and the right eye image at the same time.
The upper polaroid of the current 3D glasses, for example the shutter glasses, is characterized by a linear polaroid. When the absorption axis of the linear polaroid of the 3D glasses is parallel to the one of the upper linear polaroid of the display, the polarized light is filtered out by the 3D glasses. Therefore, when the user wears the 3D glasses in an unacceptable angle or observes an object through the 3D glasses in an unacceptable angle of view, it will cause that the image is blocked and influences the 3D observation.
Accordingly, we still need a solution which can solve the aforementioned problems of the conventional passive type 3D glasses, for example the limited wearing angle and the insufficient vertical resolution.